Newswise — Four healthy lifestyle factors—never smoking, maintaining a healthy weight, exercising regularly and following a healthy diet—together appear to be associated with as much as an 80 percent reduction in the risk of developing the most common and deadly chronic diseases, according to a report in the August 10/24 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

Cardiovascular disease, cancer and diabetes—chronic diseases that together account for most deaths—are largely preventable, according to background information in the article. "An impressive body of research has implicated modifiable lifestyle factors such as smoking, physical activity, diet and body weight in the causes of these diseases," the authors write.

To further describe the reduction in risk associated with these factors, Earl S. Ford, M.D., M.P.H., of the Centers for Disease Control and Prevention, Atlanta, and colleagues assessed data from 23,513 German adults age 35 to 65. At the beginning of the European Prospective Investigation Into Cancer and Nutrition"Potsdam (EPIC-Potsdam) study—between 1994 and 1998—participants completed an assessment of their body weight and height, a personal interview that included questions about diseases, a questionnaire on sociodemographic and lifestyle characteristics and a food frequency questionnaire.

Their responses were assessed for adherence to four healthy lifestyle factors: never smoking, having a body mass index lower than 30, exercising for at least three and a half hours per week and following healthy dietary principles (for example, having a diet with high consumption of fruits and vegetables while limiting meat consumption). Follow-up questionnaires were administered every two to three years.

Most participants had one to three of these health factors, fewer than 4 percent had zero healthy factors and 9 percent had all four factors. Over an average of 7.8 years of follow-up, 2,006 participants developed new cases of diabetes (3.7 percent), heart attack (0.9 percent), stroke (0.8 percent) or cancer (3.8 percent).

After adjusting for age, sex, education level and occupation, individuals with more healthy lifestyle factors were less likely to develop chronic diseases. Participants who had all four factors at the beginning of the study had a 78 percent lower risk of developing any of the chronic diseases during the follow-up period than those who had none of the healthy factors. The four factors were associated with a 93 percent reduced risk of diabetes, 81 percent reduced risk of heart attack, 50 percent reduced risk of stroke and 36 percent reduced risk of cancer.

The largest reduction in risk was associated with having a BMI lower than 30, followed by never smoking, at least 3.5 hours of physical activity and then adhering to good dietary principles.

"Our results reinforce current public health recommendations to avoid smoking, to maintain a healthy weight, to engage in physical activity appropriately and to eat adequate amounts of fruits and vegetables and foods containing whole grains and to partake of red meat prudently," the authors write. "Because the roots of these factors often originate during the formative stages of life, it is especially important to start early in teaching the important lessons concerning healthy living."

(Arch Intern Med. 2009;169[15]:1355-1362. Available pre-embargo to the media at www.jamamedia.org.)

Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.